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Diff upgrade

Posted: Tue Apr 28, 2020 3:52 pm
by Matth93
I’ve been thinking about fitting a limited slip diff into my car for quite a while and so have bit the bullet and gone for it.
Got the car up in the air this afternoon and stripped it out.
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The first torx bolt I tried to undo rounded off and did not want to budge so I ended up welding another bolt into it so I could get a better grip and get some heat into it, which worked as I expected. I also had to do this on one other bolt.
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The diff is now stripped the bearings look a bit pitted but I have already got replacements ready. So tomorrow I’ll clean it all up and start rebuilding
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Re: Diff upgrade

Posted: Tue Apr 28, 2020 4:35 pm
by DJ.
I'm looking forward to this thread :)

Re: Diff upgrade

Posted: Tue Apr 28, 2020 4:49 pm
by DJ.
Do you think the pitting is due to the diff not being used for some time in the past?

It's nice to see good sized taper roller bearings. When I had my diff rebuilt the chap at Road and Race showed me a bearing from a BMW 1 series diff (which Caterham changed to) and it was two ball races in a plastic cage :o

Re: Diff upgrade

Posted: Tue Apr 28, 2020 4:55 pm
by Wingco
Looks another good thread Matt, what is your diff ? Sierra ? where did you buy the LSD parts from ?
I am thinking of doing this as well, mine is an old English axlE I believe.
Good luck Matt

Re: Diff upgrade

Posted: Tue Apr 28, 2020 5:17 pm
by Matth93
Yes my diff is a Sierra one. I got the parts from Burton they are doing a good price on the Quaife atb diffs it makes them not much more expensive than the Blackline Chinese copies

Re: Diff upgrade

Posted: Tue Apr 28, 2020 7:14 pm
by Kegco
Good progress today Matt
Your soon be going for donuts :lol:

Re: Diff upgrade

Posted: Tue Apr 28, 2020 9:01 pm
by b33fy
Nice one Matt, got an atb fitted to mine, work well when needed, caught me out a couple of times though!

Re: Diff upgrade

Posted: Wed Apr 29, 2020 7:30 am
by Wingco
Mike caught me out a couple of times though!

Mike what do you mean caught me out ?
Whats the pros and cons ? for LSD
Sorry to ask on your thread Matt.

Re: Diff upgrade

Posted: Wed Apr 29, 2020 9:18 am
by DJ.
There's a very long thread on Lotus Seven Club forum about LSDs.

One camp say they are great because you don't spin a wheel coming out if slower corners and at/over the limit the car is more controllable.

The others say that they are dangerous for road use, particularly bumpy roads, because instead of just spinning one wheel, and losing speed, both wheels spin causing the rear of the car to slide and catching out a driver not expecting it.

I can see it from both sides, but do have an lsd fitted to my car *smile*

Re: Diff upgrade

Posted: Wed Apr 29, 2020 10:26 am
by nelmo
I always wondered about LSDs - this was useful: https://en.wikipedia.org/wiki/Limited-slip_differential

So, if I'm getting this right, an open diff almost acts like a traction control system (which you can't turn off) - any wheel slip and you just lose power and the slide stops (or is lessened). So I'm guessing drifting is much more tricky without an LSD? :D Great, I now have an excuse for not being able to get the back-end out for any length of time...